Key takeaways
- GSTR-1 is the statement of your outward supplies — your sales — for a month or a quarter.
- Monthly filers file by the 11th of the next month; quarterly (QRMP) filers by the 13th of the month after the quarter.
- B2B invoices are reported one by one; most B2C sales as totals by state and rate.
- Your GSTR-1 feeds your buyers’ statements, so mistakes reach your customers’ input tax credit.
What is GSTR-1?
GSTR-1 is the return in which a regular GST-registered business reports its outward supplies — the sales it made — for the period. The B2B invoices in it show up in each buyer’s own statement, which is what their input tax credit is matched against.
Businesses under the composition scheme do not file GSTR-1; they file their own simpler returns.
When it is due
| How you file | Who | Due |
|---|---|---|
| Monthly | Default for regular taxpayers | 11th of the following month |
| Quarterly (QRMP) | Aggregate turnover up to ₹5 crore, by choice | 13th of the month after the quarter |
Quarterly filers can upload B2B invoices for the first two months of a quarter through the Invoice Furnishing Facility (IFF), so their buyers can claim credit sooner.
Late fees and due dates are notified by the government and can change. Check the GST portal for the current ones.
What goes where
| Section | What it holds |
|---|---|
| B2B | Each invoice to a registered buyer, with their GSTIN |
| B2C large | Each inter-state invoice to an unregistered buyer above ₹1 lakh (since August 2024) |
| B2C small | All other B2C sales, as totals by state and rate |
| Credit and debit notes | Notes issued against earlier invoices, such as returns |
| Nil-rated, exempt and non-GST | Sales that carry no GST |
| HSN summary | Sales totals by HSN code |
| Documents issued | The invoice series used in the period, and cancelled invoices |
Filing it, step by step
- Make sure every sale of the period is billed and every return is recorded.
- Prepare the figures — on the GST portal, or as a JSON file from your billing software uploaded through the portal’s offline tool.
- Check the summary on the portal against your own sales report.
- Submit, then file with your digital signature or an EVC sent to your registered mobile.
Preparing GSTR-1 in Suiteloom
Suiteloom builds your GSTR-1 figures from your own bills for each GSTIN you bill under: B2B invoices one by one, B2C sales by state and rate, credit notes to registered buyers, nil-rated and exempt sales, and the documents issued. Download them as JSON or Excel for you or your accountant to file on the portal.
Suiteloom covers the sales you bill in it. Add any sales made elsewhere, any B2C large invoices (inter-state, over ₹1 lakh) and the HSN summary on the portal before filing.
This guide is general information, checked on 23 October 2026. It is not legal or tax advice. Rules, rates and limits are notified by the government and change; check the GST portal and official notifications, or ask your accountant, for your business.